5,458 research outputs found

    INCOME REMINDER AND THE DIVERGENCE BETWEEN WILLINGNESS-TO-PAY ESTIMATES ASSOCIATED WITH DICHOTOMOUS CHOICE AND OPEN-ENDED ELICITATION FORMATS

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    This study investigates whether an income reminder can reduce the divergence between the willingness-to-pay (WTP) estimates associated with the open-ended (OE) and dichotomous choice (DC) elicitation formats. Results show that without an income reminder, WTP estimate associated with DC elicitation format is about 1.66 times as large as that associated with OE elicitation format. With an income reminder, the WTP estimate associated with DC format decreased while the WTP estimate associated with OE format increased, and the divergence between the WTP estimates was almost eliminated.dichotomous choice, open-ended, income reminder, water quality improvement, willingness-to-pay, Research Methods/ Statistical Methods,

    Quantum Helicity Entropy of Moving Bodies

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    Lorentz transformation of the reduced helicity density matrix for a massive spin 1/2 particle is investigated in the framework of relativistic quantum information theory for the first time. The corresponding helicity entropy is calculated, which shows no invariant meaning as that of spin. The variation of the helicity entropy with the relative speed of motion of inertial observers, however, differs significantly from that of spin due to their distinct transformation behaviors under the action of Lorentz group. This novel and odd behavior unique to the helicity may be readily detected by high energy physics experiments. The underlying physical explanations are also discussed.Comment: version to appear in Journal of Physics A as a Fast Track Communicatio

    mGluR5 antagonism inhibits cocaine reinforcement and relapse by elevation of extracellular glutamate in the nucleus accumbens via a CB1 receptor mechanism.

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    Metabotropic glutamate receptor 5 (mGluR5) antagonism inhibits cocaine self-administration and reinstatement of drug-seeking behavior. However, the cellular and molecular mechanisms underlying this action are poorly understood. Here we report a presynaptic glutamate/cannabinoid mechanism that may underlie this action. Systemic or intra-nucleus accumbens (NAc) administration of the mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) dose-dependently reduced cocaine (and sucrose) self-administration and cocaine-induced reinstatement of drug-seeking behavior. The reduction in cocaine-taking and cocaine-seeking was associated with a reduction in cocaine-enhanced extracellular glutamate, but not cocaine-enhanced extracellular dopamine (DA) in the NAc. MPEP alone, when administered systemically or locally into the NAc, elevated extracellular glutamate, but not DA. Similarly, the cannabinoid CB1 receptor antagonist, rimonabant, elevated NAc glutamate, not DA. mGluR5s were found mainly in striatal medium-spiny neurons, not in astrocytes, and MPEP-enhanced extracellular glutamate was blocked by a NAc CB1 receptor antagonist or N-type Ca++ channel blocker, suggesting that a retrograde endocannabinoid-signaling mechanism underlies MPEP-induced glutamate release. This interpretation was further supported by our findings that genetic deletion of CB1 receptors in CB1-knockout mice blocked both MPEP-enhanced extracellular glutamate and MPEP-induced reductions in cocaine self-administration. Together, these results indicate that the therapeutic anti-cocaine effects of mGluR5 antagonists are mediated by elevation of extracellular glutamate in the NAc via an endocannabinoid-CB1 receptor disinhibition mechanism

    Holographic optical trapping

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    Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps useful for capturing, moving and transforming mesoscopic objects. Through a combination of beam-splitting, mode forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. With nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps offer extraordinary access to the microscopic world and already have found applications in fundamental research and industrial applications.Comment: 8 pages, 7 figures, invited contribution to Applied Optics focus issue on Digital Holograph

    Expression and processing of fluorescent fusion proteins of amyloid precursor protein (APP)

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    AbstractProcessing of β-amyloid precursor protein (APP) by β- and γ-secretases in neurons produces amyloid-β (Aβ), whose excess accumulation leads to Alzheimer's disease (AD). Knowledge on subcellular trafficking pathways of APP and its fragments is important for the understanding of AD pathogenesis. We designed fusion proteins comprising a C-terminal fragment of APP (app) and fluorescent proteins GFP (G) and DsRed (D) to permit the tracking of the fusion proteins and fragments in cells. CAD cells expressing these proteins emitted colocalized green and red fluorescence and produce ectodomains, sGapp and sRapp, and Aβ, whose level was reduced by inhibitors of β- and γ-secretases. The presence of GappR in endosomes was observed via colocalization with Rab5. These observations indicated that the fusion proteins were membrane inserted, transported in vesicles and proteolytically processed by the same mechanism for APP. By attenuating fusion protein synthesis with cycloheximide, individual fluorescent colors from the C-terminus of the fusion proteins appeared in the cytosol which was strongly suppressed by β-secretase inhibitor, suggesting that the ectodomains exit the cell rapidly (t1/2 about 20min) while the C-terminal fragments were retained longer in cells. In live cells, we observed the fluorescence of the ectodomains located between parental fusion proteins and plasma membrane, suggesting that these ectodomain positions are part of their secretion pathway. Our results indicate that the native ectodomain does not play a decisive role for the key features of APP trafficking and processing and the new fusion proteins may lead to novel insights in intracellular activities of APP

    Variation in Loblolly Pine Ring Microfibril Angle in the Southeastern United States

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    The effect of physiographic region on microfibril angle (MFA) in loblolly pine (Pinus taeda L.) in the southern United States was evaluated. MFA was determined at 1.4, 4.6, 7.6, 10.7, and 13.7 m up the stem of 59 trees, representing five physiographic regions. A nonlinear mixed-effects model was developed to test for regional differences in the initial value of MFA, the rate at which MFA changes with ring number from pith, and the lower bound of MFA achieved. Our results suggest that the parameters of interest differ significantly by region. It was found that MFA differs significantly between the South Atlantic, Gulf, and Hilly regions, compared to the North Atlantic and Piedmont regions. The initial value of MFA was found to be smaller in the Piedmont compared to all other regions. Similarly, the rate at which MFA changes with ring number was found to be significantly smaller in the North Atlantic and Piedmont regions. A test of the lower bound of MFA indicates that the Piedmont region has a significantly larger lower asymptote. These results combined indicate that overall, MFA values are larger in the North Atlantic and Piedmont regions

    Surface-based constraints on target selection and distractor rejection: Evidence from preview search

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    In preview search when an observer ignores an early appearing set of distractors, there can subsequently be impeded detection of new targets that share the colour of this preview. This “negative carry-over effect” has been attributed to an active inhibitory process targeted against the old items and inadvertently their features. Here we extend negative carry-over effects to the case of stereoscopically defined surfaces of coplanar elements without common features. In Experiment 1 observers previewed distractors in one surface (1000 ms), before being presented with the target and new distractors divided over the old and a new surface either above or below the old one. Participants were slower and less efficient to detect targets in the old surface. In Experiment 2 in both the first and second display the items were divided over two planes in the proportion 66/33% such that no new planes appeared following the preview, and there was no majority of items in any one plane in the final combined display. The results showed that participants were slower to detect the target when it occurred in the old majority surface. Experiment 3 held constant the 2D properties of the stimuli while varying the presence of binocular depth cues. The carry-over effect only occurred in the presence of binocular depth cues, ruling out any account of the results in terms of 2-D cues. The results suggest well formed surfaces in addition to simple features may be targets for inhibition in search

    Ontology-based collection, representation and analysis of drug-associated neuropathy adverse events

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    Abstract Background Neuropathy often occurs following drug treatment such as chemotherapy. Severe instances of neuropathy can result in cessation of life-saving chemotherapy treatment. Results To support data representation and analysis of drug-associated neuropathy adverse events (AEs), we developed the Ontology of Drug Neuropathy Adverse Events (ODNAE). ODNAE extends the Ontology of Adverse Events (OAE). Our combinatorial approach identified 215 US FDA-licensed small molecule drugs that induce signs and symptoms of various types of neuropathy. ODNAE imports related drugs from the Drug Ontology (DrON) with their chemical ingredients defined in ChEBI. ODNAE includes 139 drug mechanisms of action from NDF-RT and 186 biological processes represented in the Gene Ontology (GO). In total ODNAE contains 1579 terms. Our analysis of the ODNAE knowledge base shows neuropathy-inducing drugs classified under specific molecular entity groups, especially carbon, pnictogen, chalcogen, and heterocyclic compounds. The carbon drug group includes 127 organic chemical drugs. Thirty nine receptor agonist and antagonist terms were identified, including 4 pairs (31 drugs) of agonists and antagonists that share targets (e.g., adrenergic receptor, dopamine, serotonin, and sex hormone receptor). Many drugs regulate neurological system processes (e.g., negative regulation of dopamine or serotonin uptake). SPARQL scripts were used to query the ODNAE ontology knowledge base. Conclusions ODNAE is an effective platform for building a drug-induced neuropathy knowledge base and for analyzing the underlying mechanisms of drug-induced neuropathy. The ODNAE-based methods used in this study can also be extended to the representation and study of other categories of adverse events.http://deepblue.lib.umich.edu/bitstream/2027.42/134596/1/13326_2016_Article_69.pd
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